Power Characterization of a Bluetooth-Equipped Sensor Node

Wireless Sensor Networks (WSNs) consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability of WSNs in real world applications, minimizing energy consumption and size are important research topics. A WSN node itself is a complex system consisting of numerous components, and the energy consumption of the node depends heavily on the interaction between its components and their respective operation modes. To develop a power consumption model, we have investigated the power characteristics of a Bluetooth(BT)equipped node based on COTS (commercial off-the-shelf) components running standardized protocols for communication. The characterization captures the transient behavior of the individual components as well as the dynamic behavior of the system as a whole. Although the parameters of the model are derived for a specific node, the model and our conclusions can be applied to WSN nodes in general. Based on our model the estimated lifetime of a battery powered BT-equipped node can range from a couple of days to several months depending on battery and usage. This result indicates that COTS based sensor nodes can be used in a wide range of applications.